Over voltage on a power supply line is usually not a problem if the power supply circuit is designed to provide a regulated dc output voltage. In the event, however, that an over voltage is expected for whatever reason, there are at least two techniques that may be used to alleviate such a situation. In one instance, a series resistor is placed between the power supply node and the “load” circuitry that will be making use of the power. That, however, may not work for the case where an appreciable amount of current is expected to be drawn through the power supply node, because the series resistor will, in that case, cause a substantial voltage drop. Another form of over voltage protection uses an active, transient voltage suppressor device that is connected in parallel with the power supply node and ground. An example is a transient voltage suppression diode that operates by shunting excess current when the power supply node voltage exceeds an avalanche breakdown potential. This is in effect a clamping device that suppresses all over voltages above its breakdown voltage, and automatically resets when the over voltage goes away. The transient voltage suppression diode, however, may be difficult to integrate with low cost, large scale integration digital logic circuitry, e.g. in a complementary metal oxide semiconductor (CMOS) integrated circuit (“IC”) die.